(1) Field of the Invention
This invention relates to novel ternary salts of tris(aminomethyl)phosphines and their oxides, and to methods for preparing the same.
(2) Description of the Prior Art
The unsubstituted tris(aminomethyl)phosphine, (NH.sub.2 CH.sub.2).sub.3 P, is unknown. The corresponding oxide, (NH.sub.2 CH.sub.2).sub.3 PO, is accessible only through the Gabriel synthesis from tris(chloromethyl)phosphine oxide, (ClCH.sub.2).sub.3 PO [Trostyanskaya, et al., Zh. Obshch. Khim., 37, 1655-57 (1967)]. It formed a crystalline salt, m.p. above 320.degree. C., with hydrochloric acid, identified as the monohydrochloride salt by elemental analysis and molecular weight determination. Significantly, no ternary salt was reported. The fully substituted reagents, (R.sub.2 NCH.sub.2).sub.3 P(O).sub.n (R=alkyl or aryl, n=0 or 1) are accessible by the reaction of dialkylamines with tetrakis(hydroxymethyl)phosphonium chloride (THPC) [Coates and Hoye, U.S. Pat. No. 3,035,053 (1962)], tris(acetoxymethyl)phosphine [Mironova et al., Zh. Obshch. Khim., 42, 2152-58 (1972)], or white phosphorus and formaldehyde [Maier, U.S. Pat. No. 3,359,266 (1967)], or by the reaction of diarylamines with neutralized THPC [Daigle et al., Text. Research J., 40, 580-81 (1970)]. The partially substituted reagents, (RNHCH.sub.2).sub.3 P(O).sub.n (R=aryl, n=0 or 1) are accessible by the reaction of arylamines with THPC [Frank and Drake, Jr., U.S. Pat. No. 3,987,098 (1976)] and other methods described therein; those reagents in which R=alkyl, n=0 or 1 are, to the best of our knowledge, unknown.